Arctic Plants: Geographical Distribution 115 b 



With regard to the Pyrolaceae, several of the other species have also been 

 recorded from the arctic region, notably from Greenland, arctic Scandinavia, 

 and arctic Russia, but none from Spitzbergen nor from arctic Siberia; in other 

 words, the genera do not contain any circumpolar species. While studying the 

 geographical distribution of some of the species, notably the arctic ones, I have 

 noticed several points which might be useful to the location of their centres, and 

 for this reason I have thought it appropriate to insert a table (Table 6) showing 

 their distribution, principally in the northern regions of both Worlds. No species 

 has, so far, been reported from the southern hemisphere. Pyrola is credited to 

 the northern and central parts of both Worlds, including Mexico; the monotypic 

 Moneses to northern and Central Europe, Asia, including Japan, and the northern 

 and middle parts of this continent; Chimaphila shows the same distribution, 

 but including Mexico, Santo Domingo, and Corea. 



Besides the species I have enumerated several varieties in order to illustrate 

 the development of the species in the various countries. With regard to Chima- 

 phila, C. maculata and C. Menziesii are confined to this continent, the latter 

 being mainly a western type, the former an eastern. C. umbellata, on the other 

 hand, extends from the Atlantic to the Pacific slope; moreover, it occurs in Europe 

 from the southern parts of Scandinavia, through Denmark and Germany to 

 Switzerland (Zurich) ; it is not known from England, Scotland, or Ireland, accord- 

 ing to Babington.i In Asia C. umbellata is known from Manchuria, Altai and 

 Baikal mountains. 



Four varieties have been recognized of C. umbellata, namely: cisatlantica 

 Blake from Quebec, New Brunswick, Prince Edward Island, and Nova Scotia, 

 to western Ontario and Minnesota, southward to Virginia; occidentalis (Rydb.) 

 Blake from British Columbia to Colorado, and the mountains of north-central 

 Cahfornia; mexicana DC. from southern Mexico; acuta (Rydb.) Blake from New 

 Mexico and TU-izona. These varieties have been very carefully described and 

 discussed by Dr. S. F. Blake ^ who, furthermore, has segregated the Santo 

 Domingo representative of C umbellata as C. domingensis Blake,' endemic to 

 this island. 



According to Maximowicz (Flor. Amur. I.e.) a fifth species, C. japonica 

 Miq. (C. astyla Maxim.), is a native of Japan and Manchuria. 



C. umbellata and C. maculata are lowland plants, sylvan types, which no- 

 where enter the arctic region; they evidently originated on the Atlantic slope, 

 but the occurrence of the former on the Asiatic coast of Bering strait, in Man- 

 churia and Altai, and also in Central Europe, may indicate a former, much wider 

 distribution, but disconnected at present. The fact that the genus is best repre- 

 sented on this continent, with three closely allied species, seems to be in favour 

 of locating the centre of the genus on this continent. 



A much wider distribution is exhibited by Moneses which furthermore has 

 been recorded from Manchuria (Maximowicz I.e.). It enters the arctic region 

 in Scandinavia and Russia but nowhere in Siberia, nor on this continent; in 

 Europe it extends as far south as the Alps and Pyrenees but is not alpine, and on 

 this continent to Colorado. The occurrence of Moneses in arctic Europe may 

 indicate that it is one of the temperate plants which accompanied the arctic on 

 their retreat to the north, and it seems most natural, I think, to attribute a 

 southern centre to the species, or let us say genus, since it is monotypic. But 

 where in the south is impossible to decide. 



In both Worlds it inhabits shady or mossy woods, especially coniferous, 

 and it is, more or less, associated with the same species of Pyrola. It is remark- 

 ably constant in its habit, and no variety has, as far as I know, been reported. 

 Although a native of the Altai and Baikal mountains, Moneses has not become 



1 Manual of British Botany. 7th ed. London, 1874. 



2 Rhodora, Vol. 19, p. 237. Boston, 1917. 



3 Journ. Botany LII, p. 169. London, 1914. 



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